Control method and means



June 29, 1954 D. G. c. HARE 2,682,144

CONTROL METHOD AND MEANS Filed March 18, 1947 4 Sheets-Sheet 1 '1 .l. 5T q 20 3 Con+ro\ Feed Rollers i Mechanism 1 l 76* l 23 I .Dmfi RollersIT 16 name e r S w/o su/ $522; MW

im l 2 L T2 36 gimp wire! mechamsm 12/ a4 INVENTOR DONALD G. C. HAREJune 29, 1954 D. G. C. HARE CONTROL METHOD AND MEANS Filed March 18,1947 4 Sheets-Sheet 2 a, A ORNEY June 1954 D. G. c. HARE CONTROL METHODAND MEANS 4 Sheets-Sheet 5 Filed March 18, 1947 INVENTOR DONALD 6.0.HARE June 29, 1954 D. cs. 0. HARE 2,682,144

CONTROL METHOD AND MEANS Filed March 18, 1947 4 Sheets-Sheet 4 Con'l-rolLiqlq] INVENTOR DONALD 6.0 HARE Patented June 29, 1954 UNITED STATESPATENT OFFICE CONTROL METHOD AND MEANS Donald G. C. Hare, Clemson, S.0., assignor to Deering Milliken Research Trust, New York, N. Y., anonprofit trust of New York Application March 18, 1947, Serial No.735,457

7 Claims. 1

My present invention relates to methods and means for control ofdimensions of materials during manufacture. My invention is particularlyadapted for continuous control of yarn diameter during the spinningoperation but the broad features of the invention have a much widerapplication, as will be apparent as the description proceeds. Theinvention, as applied to yarn diameter control, is applicable to anytype of yarn, whether formed from staple fibers or from continuousfilament, and may be employed to control the spinning operation ofdirect towto-yarn as Well as of the usual roving to yarn spinner.

Workers in the textile industry have devised various mechanisms formeasuring and recording yarn diameters but so far as I am aware no onehas heretofore suggested or disclosed how such mechanisms could be usedto insure substantial uniformity in yarn diameter. In accordance withthe preferred embodiment of the present invention, as applied to yarndiameter control, I utilize any suitable means that is responsive toyarn diameter variations to control, through a suitable servo-mechanism,an element of the yarn spinning mechanism that affects the diameter ofthe yarn being spun. More specifically, and as applied to the usualspinning mechanism wherein roving is drawn by draft rollers from feedrollers rotating at a lower speed than the draft rollers and the yarn iswound on a rapidly rotating spindle, I position the yarn diameterresponsive device preferably between the draft rollers and spindle andcontrol from that device the draft ratio, that is, the ratio of theperipheral speed of the draft rollers to that of the feed rollers.Various means may be utilized for adjusting the draft ratio to controlyarn diameter and various yarn diameter responsive devices may beemployed. In the accompanying drawings I have indicated more or lessdiagrammatically various types of mechanisms suitable for carrying outthe method of the invention.

Fig. 1 is a diagram indicative of apparatus embodying the invention andoperative to control yarn diameter;

Figs. 2, 2a, 3, 4, and 5 are diagrams illustrating alternative yarndiameter responsive devices suit- I able for use as one element of theequipment of Fig. 1;

Figs. 6, 7, 7a, 8 and 80: are diagrams illustrating alternativemechanisms for controlling the In Fig. 1 a conventional unit of aspinning machine is indicated as comprising the spindle 2, with itstraveller 4, the draft rollers 6 and feed rollers 8. Only one roller 6and one roller 8 is shown in the drawings but it will be understood thatthe draft rollers comprise one driven roller and one idler rollerbetween which the rovings I0 pass and emerge as yarn l2 and similarlythe feed rollers comprise one driven and one idler roller between whichthe rovings l0 pass. In accordance with the preferred embodiment of theinvention, the yarn I2 during its travel from the draft rollers 6 to theyarn guide l4 passes through a device [6 which responds to variations inthe diameter of the yarn and which operates, upon departure of the yarndiameter from a predetermined value, to actuate a servo-motor [8. Themotor [8 in turn operates to actuate a control mechanism 20 to adjustthe draft ratio in a direction to return the yarn diameter to thepredetermined value or range. Mechanism 20 may adjust the draft ratio byadjustment of the rate of delivery of the feed rollers as indicated bythe line 2! or by adjustment of the rate of delivery of the draftrollers as indicated by the line 23, or by both such adjustments.Preferably, mechanism 20 controls the rate of delivery of the feedrollers.

Various mechanisms could be used for the device l 5 of Fig. 1, andexamples of suitable devices are illustrated diagrammatically in Figs. 2through 5.

In Figs. 2 and 2a, photoelectric means responsive to yarn diameter areillustrated. In Fig. 2 a photocell 26 is positioned to receive lightfrom a suitable source 24 after its passage through a lens system 22 aslot 25 being positioned between parts of the lens system. The yarn I 2passes between the photocell 26 and lens system 22 so as to interceptsome of the light. A second, or balancing, photocell 28 is positioned toreceive light from source 24 after passage through a, slot 30. Thepositive terminal of a battery 32 is connected to the anode of cell 28,and the negative terminal of that battery is connected to ground and tothe positive terminal of a battery 34, of equal voltage, and of whichthe negative terminal is connected to the cathode of cell 26; thecathode of cell 28 and anode of cell 26 being connected together by alead 36. A resistor 38 has one end grounded and its other end connectedto lead 36. An amplifier 42 is connected across the resistance 38. Withthe above described arrangement, when the current through the photocellsare equal, no current flows through the resistor 38, and no potentialdifference appears across the input terminals of the amplifier. Suitableadjustment, as of 3 the distance of cell 28 to the light source 24, orof the size of slot 30, or the like, may be made to insure equal currentthrough the photocells when the diameter of the yarn i2 is that desired.If then, the diameter of the yarn increases at any time, the currentthrough cell 26 decreases with the result that the potential of lead 36will be positive with respect to ground and current will flow throughresistor 38, and a potential difference of a magnitude depending uponthe change in yarn diameter will be applied across the amplifier inputterminals. The amplified voltage appearing across the output terminalsof the amp-li fier can then be used, as hereinafter described inconnection with Figs. 6 to Sc inclusive, to increase the draft ratiountil the voltage across resistor 38 returns to zero, indicating areturn of yarn diameter to the desired diameter.

Conversely, when the yarn diameter is less than that desired, thecurrent through photocell 26 exceeds that through cell 28 and thepotential of lead 36 becomes negative, causing application of potentialdifference across the amplifier input terminal in a direction to causereduction in draft ratio.

Instead of arranging photocells to respond, as in Fig. 2, to the directlight from a source, the response could be by reflected light asindicated diagrammatically in Fig. 2a. In this embodiment of theinvention, light from a source 25a, after passage through a lens 22c,illuminates the yarn i2 and a photocell 26a is positioned to receivelight reflected from the yarn surface. A resistor 38a and battery 34aare connected in series With the cell 26a. Thus the current through thecell is dependent upon the diameter of the yarn and variations of suchcurrent from a value corresponding to the desired yarn diameter can beutilized to control draft ratio. For example the indicating needle ii of2. voltmeter 43 connected across the resistor 38a could close onecircuit of a reversible motor 16 when the voltage across resistor 38aincreases to a predetermined value and could close the other circuit ofthe motor when the voltage drops to a predetermined figure; rotation ofthe motor in one direction, that caused by excess current through thecell 26a operating to increase the draft ratio and rotation of the motorin the other direction caused by too little current through the cell 26aoperating to decrease the draft ratio.

In Fig. 3 the yarn diameter responsive device includes a capillary tube48 through which the yarn passes, and from which air is drawn by suctionapplied to a branch tube 453. A resistor 50 is positioned in the branchpipe 69 and is supplied with current from a battery 52. If a constantsuction is applied to the pipe 49, the air flow past the resistor 50will vary with the diameter of the yarn and consequently the temperatureof resistor 58 and hence its resistance Will vary accordingly.Variations in current through the resistor 50 can be suitably amplifiedand utilized for control of draft ratio.

In Fig. 4 control in response to variations in capacity resulting fromyarn diameter variations is indicated; the yarn I2 passing betweenplates 54 and 56 of an air condenser so as to affect the capacitythereof.

Fig. illustrates diagrammatically a contact method of determining yarndiameter. In this arrangement the yarn i2 passes between a fixed surface58 and a light roller 60 carried on one end of a pivoted rod 62. Theroller will follow variations in thickness of the yarn and causerotation of lever 62. Such rotation may be utilized to vary a resistanceas diagrammatically illustrated. Such resistance variations, afteramplification can be made to generate suitable control signals.

Various yarn diameter responsive devices have now been briefly describedin connection with Figs. 2 to 5 inclusive. The invention in its broadestaspect is not concerned, however, with the particular device employed asany device which responds to yarn diameter variations while the yarn ismoving would be suitable for use as the device I6 ofFig. l. Nor is theparticular type of control signal obtained from the responsive deviceimportant as electrical, mechanical, pneumatic or hydraulic controlsignals could readily be utilized by those skilled in the art forcontrol of the draft ratio of the spinning unit of Fig. 1. For thisreason, and for simplicity, the alternative mechanisms, illustrateddiagrammatically in Figs. 6 to 8a inclusive and now to be described havebeen indicated as solenoid actuated but other types of actuation couldas readily be employed.

In Fig. 6 control of draft ratio is effected by varying the rate ofrotation of the driven feed roller 8. The driven roller 8 is driventhrough spur gears 64 by a shaft 66, which shaft is coupled to a driveshaft 68 through a fluid coupling 70. The liquid level Within thecoupling TD, and therefore the degree of coupling or slip between shafts66 and 58 is controlled by expansion and contraction of a bellows I2which in turn is controlled by the solenoid l4 acting in opposition to aspring 16. Thus variations in yarn diameter transmitted as controlsignals to the winding of coil .14 operate to change the rate ofrotation of the feed roller 8 in directions and by amounts sufficient toeliminate the variations.

Instead of changing the rate of rotation of the driven feed roller asindicated in Fig. 6, the arrangement indicated diagrammatically in Fig.'7 could be employed. In this case, the driven feed roller 8a is oftapered diameter and is driven at a constant rate of rotation. Therovings If] as they pass to the feed rollers are collected in a trumpet18 and the position of this trumpet longitudinally along the feed roller8a is controlled by the solenoid H in response to the control signal.When the trumpet 18 moves the rovings to that end of roller 8a havingthe largest diameter and hence the highest peripheral speed, the draftratio is at a minimum and conversely when the trumpet 18 moves therovings to the other end of roller 8a, the draft ratio is a maximum.

In Fig. 7a the same type of control, as just described, namely the useof a trumpet for moving the roving longitudinally along tapered rollersis indicated as applied to the draft rollers 6a. In this case, as thedraft ratio is controlled by adjustment of the draft rollers, the rateof delivery of the yarn [2 will vary with changes in the position of thetrumpet 18. If it is desired to avoid corresponding variations in thenumber of turns of yarn per unit length on the spindle the rate ofrotation of the spindle 2 can be varied concurrently with change intrumpet position, as, for example, by control of a friction clutch froma solenoid Ma connected in parallel with solenoid 14; the clutch 80serving to couple the spindle to the constant speed driven shaft 82.

In Fig. 8. as in Fig. 6, the draft ratio is controlled by control of therate of rotation of the driven feed roller 8. In this embodiment of theinvention the shaft. 84 of the drivenroller 8 is coupled toa shaft 86.by a connection permitting, relative longitudinal motionof the twoshafts. For example, the shaft 84lmaybe tubular and be provided with aplurality of longitudinal slots and the shaft 86 may extend into theshaft 84 and be provided with pine extending into the 1ongitudinalslots. Shaft 86 has fixed thereto a generally spherical member 88 forfrictional enagementwith'a conical roller, 9:3 driven at a constant rateby drive shaft 92. With this arrangement, the rate of rotationof feedroll 8 depends upon the diameter of the roller 90 at the point ofcontact with member 88 and hence control of draft ratio is effected bylongitudinal movement of shaft 86 undercontrol of solenoid 14; theangular position of shaft 92 relative to shaft 86 being such as toinsure engagement of member 88 at any desired diameter of roller 90.

In Fig. 8a another form of variable coupling between the conical roller90 and the shaft of feed roller 8 is indicated; In this arrangement theshaft of roll 8 is connected bya suitable universal coupling 9| to ashaft 86a to which is keyed a member 88a. of varying diameter. Theangular position of shaft 86a, relative to the shaft of the roll 8controls the point of engagement of member 88a with conical roller 90and hence the rate of rotation of the roll 8 the angular position ofshaft 860. being controlled by the solenoid 14.

The invention as applied to yarn diameter control has now been describedwith reference to a unit of a conventional machine for spinning yarnfrom rovings. Obviously the invention is equally applicable for thecontrol of yarn diameter by control of draft ratio in a machine forspinning yarn directly from tow. The invention is applicable also to thecontrol of diameter of drawn filaments such as glass, and suchapplication of the invention is diagrammatically illustrated in Fig. 9.

In Fig. 9, 93 represents a nozzle through which the filament l2a isdrawn from the molten bath 94 by the rotation of a drum 96; the rate ofrotation of the drum, assuming constant temperature of the bath,determining the elongation and hence diameter of the filament. Inaccordance with the invention, the filament I; is passed through adiameter responsive device 50., which may be of the type indicated inFigs. 2 through 4 inclusive. Device 16a operates through a suitableservomotor Illa to control, through a control mechanism 20a, the rate ofrotation of the drum 96. The device [6a may be responsive to thediameter of a single filament or to the average of a plurality offilaments if desired. The same type of control, namely of the rate ofrotation of the receiving drum to vary the tension on the filament inresponse to filament diameter could be utilized for the control of thediameter of extruded filaments.

In the foregoing description of the invention as applied to maintenanceof substantial constancy of diameter of yarn or of filaments, nothinghas been said about insurance against hunting of the regulators, asanti-hunting regulation is well known and specific illustration ofdevices to prevent over travel of the control means in any particulardevice is not deemed necessary.

In some instances it might be desired to change the diameter of a yarnor filament at regular or irregular intervals and at the same timeinsure correct diameter during such intervals. To effect this result, ifthe periodicity of the desired changes in diameter are large compared tothe rate of travel of the yarn or filament it would only be necessary tochange the bias of the diameter responsive device, that is, the valuecorrespondingto the desired diameter, at a rate corresponding to theperiodicity of the desired diameter changes. Such an arrangement mightbe advantageously employed in wire drawing operation to vary die sizeperiodically and thereby obtain a wire of diameter changing inaccordance with any desired pattern, or in yarn manufacture to produce aslubby yarn.

The invention has now been described with reference to variousembodiments thereof. The invention is of particular utility in thetextile industry and particularly important when used to controldiameter of worsted yarns. Many expensive and time consuming doublingoperations are ordinarily practiced on worsted rovings in an.

attempt to insure uniform roving diameter. By means of the presentinvention, most, if not all, of these doubling operations may beomitted. Rovings of non-uniform diameter may be delivered to a spinningmachine equipped with apparatus of the invention and automatic controlof draft ratio will insure yarn of substantially uniform diameter,irrespective of the diameter of the rovings.

Although I prefer, when controlling yarn diameter, to position thediameter responsive device between the draft rollers and the spindle,this is not essential as the diameter of the roving in the ratch varieswith the diameter of the yarn and hence, measurement of roving diametercould be utilized in control of yarn diameter. Thus, the diameterresponsive device could be positioned in the ratch, between the feed anddraft rollers, or diameter measurement could be made directly at thenips of the draft rollers.

By filamentary material in the accompanying claims I intend to includeyarn and rovings,

I as well as wire, glass or other synthetic filaments to which the termis more often applied.

I claim:

1. The method of controlling a yarn spinning machine to maintainsubstantially constant yarn diameter which comprises automaticallyadjusting the draft of the machine in response to variations in thediameter of the drafted yarn while maintaining a constant relationshipbetween the rate of feed of yarn and rotation of the spindle.

2. The method of controlling a yarn spinning machine to maintainsubstantially constant yarn diameter which comprises automaticallyadjusting the rate of feed of the draft rollers in response tovariations in the diameter of the drafted yarn and simultaneouslyadjusting the rate of rotation of the spindle to maintain constantrelationship between the rate of feed of yarn and rotation of thespindle.

3. The combination with a yarn spinning machine having driven feed anddraft rollers and a driven spindle for twisting the drafted material ofa device responsive to variations in diameter of drafted material at apoint in its path between the said draft rollers and the spindle andadapted to produce an electrical control signal upon departure of thediameter of the material from a predetermined value, means foramplifying the signal produced by said device and means actuated by saidamplified control signal for adjusting the rate of delivery of the draftrollers in a direction to compensate for the departure in materialdiameter initiating said signal and for 7. simultaneously adjusting therate of rotation of said spindle to maintain a constant relationshipbetween the rate of feed of yarn and rotation of the spindle.

4. The combination according to claim 3 wherein said last mentionedmeans operates upon actuation to change the rate of rotation: of thedraft rollers.

5. The combination according to claim 3- wherein the draft rollers areof conical contour and said last mentioned means operates, whenactuated, to vary the location along the draft roller at which therovings are fed.

6a The combination with a yarn spinning machine havine' draft and feedrollers and a spindle of a device responsive to variations in diameterof the yarn being spun, and means controlled by said device formaintaining a constant relationship between the rate of feed of yarn androtationof said spindle.

7. The combination with a yarn spinning machine having draft and feedrollers and a spindle of a device responsive to variations in diameterof the yarn being spun, and means controlled by said device foradjusting the rate of speed of said 8. draft rollers and simultaneouslyadjusting: the rate of rotation of. said spindle'to maintain constantrelationship between the. rate of feed of yarn and rotationof thespindle.

References Cited in the file of this. patent UNITED STATES PATENTSNumber Name Date 68,741 Herrschaft Sept. 10, 1867 186,323 Draper Jan.16, 1877 887,281 Smith May 12, 1908 1,102,334 Good July 7, 1914'1,594,958 Howie Aug; 3, 1926' 1,791,289 Scott Feb. 3, 1931 1,796,391Owen Mar. 17, 1931 2,199,396 Dubilier .May 7, 1940 2,229,489 BarnardJan. 21', 1941 2,361,217 Lewis Oct. 24, 1944 2,378,595 Tasso June 19,1945 2,407,100 Richardson Sept. 3,1946 2,418,492 Alfthan et a1 Apr. 8,1947 FOREIGN PATENTS Number Country Date 378,779 Great Britain Aug. 18,1932

